1) Bandwith is never unlimited. Dare you to try and push 20tb. You'll probably be kicked off around 300-500 gigs.
2) Guaranteed uptime is bullshit unless they have a 99.9% Uptime SLA. The different between "Guaranteed 99.9% uptime" and "99.9% Uptime SLA" is that the first is marketing. The second is a commitment from the host. If they fail to deliver, you get discounts/free hosting. If they say anything about a % uptime and you can't find the SLA in their legal section, skip them.
3) Disk space is also limited. If it says unlimited, try hosting many large files.
What you should be looking for in quality hosting:
1) Limited space, limited bandwith. If a host gives you limits, you know what they are and the host knows what they can expect. Its a win for both parties.
2) Uptime SLA. No SLA, no signup.
3) Good reviews on webhostingtalk.com . Usually if I don't see any reviews or the company advertising on there, I skip them as well.
4) Upgrade paths. This may not be useful to you since you're just starting out with a blog but I usually look to see what the upgrade path is. Do they offer a VPS, Dedicated, Cloud? If so, will their offerings and pricing be inline with my expected requirements?
5) Response time. Send in a ticket at 2am their time with alot of questions and gauge their response time. Anything over 18 hours is an immediate no.
6) Hardware and software. I also like to see what they have to offer on both. Hardware I'm mainly looking to see if they use 7200 sata, 15k SAS, SSD RAID 10 etc... Essentially what type of performance I can expect from that. Then I look at what control panel they offer. When I'm in a rush or lazy, I go for cpanel (shared) or cpanel+whm (vps/dedi). Also, what are they using to serve websites? Normally its apache, but for faster load/response times you should be looking at litespeed, nginx, cherokee etc.
7) Do they offer a dedicated IP? Most of my sites are ecommerce or require secure viewing which means a dedicated IP for SSL certificates.
I know what I want, I know what it normally costs and I don't expect anything less than top quality for anything I deem mission critical. If you're not banking hard, you can just go with hostgator. Easy $7/month hosting with decent support and not horribly oversold servers.